37074 Federal Register / Vol. 63, No. 131 /Thursday, July 9, 1998 / Proposed Rules

replace it with an inboard wheel half having

P/N 2607046, S/N 5899 or greater, or S/N H–

1722 or greater. And

(2) Remove any outboard wheel half

specified in paragraph (b) of this AD, and

replace it with an outboard wheel half having

P/N 2607047, S/N B–5899 or greater, or S/N

H–0864 or greater.

(c)(1) An alternative method of compliance

or adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Seattle

Aircraft Certification Office (ACO), FAA,

Transport Airplane Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, Seattle ACO.

(c)(2) Alternative methods of compliance,

approved previously in accordance with AD

97–17–01, amendment 39–10102, are

approved as alternative methods of

compliance with this AD.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

(d) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

Issued in Renton, Washington, on July 1,

1998.

Stewart R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–18159 Filed 7–8–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket 97–NM–242–AD]

RIN 2120–AA64

Airworthiness Directives; McDonnell

Douglas Model DC–8 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Model DC–8 series airplanes.

Among other things, this proposal

would require repetitive leak tests of the

lavatory drain systems and repair, if

necessary; installation of a lever lock

cap, vacuum breaker check valve or

flush/fill line ball valve on the flush/fill

line; periodic seal changes; and

replacement of ‘‘donut’’ type waste

drain valves installed in the waste drain

system. This proposal is prompted by

continuing reports of damage to engines,

airframes, and to property on the

ground, caused by ‘‘blue ice’’ that forms

from leaking lavatory drain systems on

transport category airplanes and

subsequently dislodges from the

airplane fuselage. The actions specified

by this proposed AD are intended to

prevent such damage associated with

the problems of ‘‘blue ice.’’

DATES: Comments must be received by

August 24, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 97–NM–

242–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Walter Eierman, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130L, FAA, Los Angeles Aircraft

Certification Office, 3960 Paramount

Boulevard, Lakewood, California

90712–4317; telephone (562) 627–5336;

fax (562) 627–5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed rule by submitting such

written data, views, or arguments as

they may desire. Communications shall

identify the Rules Docket number and

be submitted in triplicate to the address

specified above. All communications

received on or before the closing date

for comments, specified above, will be

considered before taking action on the

proposed rule. The proposals contained

in this notice may be changed in light

of the comments received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report

summarizing each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 97–NM–242–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Transport Airplane Directorate,

ANM–114, Attention: Rules Docket No.

97–NM–242–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

Over the past several years, the FAA

has received numerous reports of

leakage from the lavatory service

systems on in-service transport category

airplanes that resulted in the formation

of ‘‘blue ice’’ on the fuselage. In some

instances, the ‘‘blue ice’’ subsequently

dislodged from the fuselage and was

ingested into an engine. In several of

these incidents, the ingestion of ‘‘blue

ice’’ into an engine resulted in the loss

of an engine fan blade, severe engine

damage, and the inflight shutdown of

the engine. In two cases, the loads

created by the ‘‘blue ice’’ being ingested

into the engine resulted in the engine

being physically torn from the airplane.

Damage to an engine, or the separation

of an engine from the airplane, could

result in reduced controllability of the

airplane.

The FAA also has received reports of

at least three incidents of damage to the

airframe of various models of transport

category airplanes that was caused by

foreign objects dislodged from the

forward toilet drain valve and flush/fill

line. One report was of a dent on the

right horizontal stabilizer leading edge

on a Boeing Model 737 series airplane

that was caused by ‘‘blue ice’’ that had

formed from leakage through a flush/fill

line; in this case, the flush/fill cap was

missing from the line at the forward

service panel. Numerous operators have

stated that leakage from the flush/fill

line is a significant source of problems

associated with ‘‘blue ice.’’ Such

damage caused by ‘‘blue ice’’ could

adversely affect the integrity of the

fuselage skin or surface structures.

Additionally, there have been

numerous reports of ‘‘blue ice’’

dislodging from airplanes and striking

houses, cars, buildings, and other

occupied areas on the ground. Although

there have been no reports of any person

being struck by ‘‘blue ice,’’ the FAA

considers that the large number of

reported cases of ‘‘blue ice’’ falling from

lavatory drain systems is sufficient to

support the conclusion that ‘‘blue ice’’

presents an unsafe condition to people

on the ground. Demographic studies

have shown that population density has

increased around airports, and probably

will continue to increase. These are
Federal Register / Vol. 63, No. 131 /Thursday, July 9, 1998 / Proposed Rules 37075

populations that are at greatest risk of

damage and injury due to ‘‘blue ice’’

dislodging from an airplane during

descent. Without actions to ensure that

leaks from the lavatory drain systems

are detected and corrected in a timely

manner, ‘‘blue ice’’ incidents could go

unchecked and eventually someone may

be struck, perhaps fatally, by falling

‘‘blue ice.’’

Current Rules

In response to these incidents, the

FAA has issued several AD’s applicable

to various transport category airplanes,

and is currently considering additional

rulemaking to address the problems

associated with ‘‘blue ice’’ on other

transport category airplanes.

Discussion of the Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other products of this same

type design, the FAA is proposing this

AD, which would require the following

actions:

Paragraph (a) of the proposed AD

would require periodic replacement of

the valve seals of each lavatory drain

system with new valve seals. This

paragraph also would require repetitive

leak tests of the lavatory dump valve

and drain valve (either service panel or

in-line drain valve). The leak test of

panel valves would be required to be

performed with a minimum of 3 pounds

per square inch differential pressure

(PSID) applied across the valve. If any

leak is discovered during the leak

checks, operators would be required

either to repair the leak and retest it, or

drain the lavatory system and placard it

inoperative until repairs can be made.

In cases where the panel valve has

both an inner seal and an outer cap seal,

perform a visual inspection for damage

or wear of the outer cap seal and seal

surface. Any damaged parts detected

would be required to be repaired or

replaced prior to further flight, or the

lavatory drained and placarded

inoperative until repairs can be made.

Paragraph (a) of the proposed AD also

requires replacement of all donut type

drain system valves with another type of

FAA-approved valve.

Additionally, the flush/fill line antisiphon valve would be required to be

leak checked. Seals of the anti-siphon

(check) valve, flush/fill line cap, or

flush/fill line ball valve would be

required to be replaced periodically.

Paragraph (b) of the proposed AD

would require that all operators install

a lever lock cap on the flush/fill lines

for all service panels, or install a flush/

fill ball valve Kaiser Electroprecision

part number series 0062–0009 on the

flush/fill lines for all lavatories.

Paragraph (c) of the proposed AD

would require that, before an operator

places an airplane into service, a

schedule for accomplishment of the leak

tests required by this AD shall be

established. This provision is intended

to ensure that transferred airplanes are

inspected in accordance with the AD on

the same basis as if there were

continuity in ownership, and that

scheduling of the leak tests for each

airplane is not delayed or postponed

due to a transfer of ownership.

Airplanes that have previously been

subject to the AD would have to be

checked in accordance with either the

previous operator’s or the new

operator’s schedule, whichever would

result in the earlier accomplishment

date for that leak test. Other airplanes

would have to be inspected before an

operator could begin operating them or

in accordance with a schedule approved

by the FAA Principal Maintenance

Inspector (PMI), but within a period not

to exceed 200 flight hours.

Economic Impact

There are approximately 306 Model

DC–8 series airplanes of the affected

design in the worldwide fleet. The FAA

estimates that 229 airplanes of U.S.

Registry and 26 U.S. operators would be

affected by this proposed AD.

The proposed waste drain system leak

test and outer cap inspections would

take approximately 6 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact on U.S.

operators of the waste drain system leak

test and outer cap inspection is

estimated to be $82,440, or $360 per

airplane, per test/inspection.

Certain airplanes (i.e., those that have

‘‘donut’’ type drain valve installed) may

be required to be leak tested as many as

15 times each year. Certain other

airplanes having other valve

configurations would be required to be

leak tested as few as 3 times each year.

Based on these figures, the cost impact

of this proposed requirement is

estimated to be between $1,080 and

$5,400 per airplane per year.

With regard to replacement of

‘‘donut’’ type drain valves, the cost of a

new valve is approximately $1,200.

However, the number of leakage tests for

an airplane that flies an average of 3,000

flight hours a year is reduced from 15

tests to 3 tests, which essentially pays

for the cost of the replacement valve, so

that no additional net cost is incurred

because of this change.

The FAA estimates that it would take

approximately 1 work hour per airplane

to accomplish a visual inspection of the

service panel drain valve cap/door seal

and seal mating surfaces, at an average

labor rate of $60 per work hour. As with

leak tests, certain airplanes would be

required to be visually inspected as

many as 15 times or as few as 3 times

each year. Based on these figures, the

cost impact of the proposed repetitive

visual inspections is estimated to be

between $180 and $900 per airplane per

year.

The proposed installation of the

flush/fill line cap would take

approximately 1 hour per cap to

accomplish, at an average labor rate of

$60 per work hour. The cost of required

parts would be $275 per cap. There are

an average of 2.5 caps per airplane.

Based on these figures, the cost impact

on U.S. operators of these proposed

requirements is estimated to be

$171,178, or $748 per airplane.

The proposed seal replacements of the

drain valves required by paragraph (a) of

this AD would require approximately 2

work hours to accomplish, at an average

labor cost of $60 per hour. The cost of

required parts would be $200 per each

seal change. Based on these figures, the

cost impact on U.S. operators of these

proposed requirements of this AD is

estimated to be $73,280, or

approximately $320 per airplane, per

replacement.

The number of required work hours,

as indicated above, is presented as if the

accomplishment of the actions proposed

in this AD were to be conducted as

‘‘stand alone’’ actions. However, in

actual practice, these actions could be

accomplished coincidentally or in

combination with normally scheduled

airplane inspections and other

maintenance program tasks. Therefore,

the actual number of necessary

‘‘additional’’ work hours would be

minimal in many instances.

Additionally, any costs associated with

special airplane scheduling should be

minimal.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the current or proposed requirements of

this AD action, and that no operator

would accomplish those actions in the

future if this AD were not adopted.

The FAA recognizes that the

obligation to maintain aircraft in an

airworthy condition is vital, but

sometimes expensive. Because AD’s

require specific actions to address

specific unsafe conditions, they appear

to impose costs that would not

otherwise be borne by operators.

However, because of the general

obligation of operators to maintain

aircraft in an airworthy condition, this
37076 Federal Register / Vol. 63, No. 131 /Thursday, July 9, 1998 / Proposed Rules

appearance is deceptive. Attributing

those costs solely to the issuance of this

AD is unrealistic because, in the interest

of maintaining safe aircraft, prudent

operators would accomplish the

required actions even if they were not

required to do so by the AD.

A full cost-benefit analysis has not

been accomplished for this AD. As a

matter of law, in order to be airworthy,

an aircraft must conform to its type

design and be in a condition for safe

operation. The type design is approved

only after the FAA makes a

determination that it complies with all

applicable airworthiness requirements.

In adopting and maintaining those

requirements, the FAA has already

made the determination that they

establish a level of safety that is costbeneficial. When the FAA, as in this

AD, makes a finding of an unsafe

condition, this means that the original

cost-beneficial level of safety is no

longer being achieved and that the

required actions are necessary to restore

that level of safety. Because this level of

safety has already been determined to be

cost-beneficial, a full cost-benefit

analysis for this AD would be redundant

and unnecessary.

Regulatory Impact

The regulations proposed herein

would not have substantial direct effects

on the States, on the relationship

between the national government and

the States, or on the distribution of

power and responsibilities among the

various levels of government. Therefore,

in accordance with Executive Order

12612, it is determined that this

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I

certify that this proposed regulation (1)

is not a ‘‘significant regulatory action’’

under Executive Order 12866; (2) is not

a ‘‘significant rule’’ under the DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3) if

promulgated, will not have a significant

economic impact, positive or negative,

on a substantial number of small entities

under the criteria of the Regulatory

Flexibility Act. A copy of the draft

regulatory evaluation prepared for this

action is contained in the Rules Docket.

A copy of it may be obtained by

contacting the Rules Docket at the

location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration proposes to amend part

39 of the Federal Aviation Regulations

(14 CFR part 39) as follows:

PART 39—AIRWORTHINESS

DIRECTIVES

1. The authority citation for part 39

continues to read as follows:

Authority: 49 U.S.C. 106(g), 40101, 40113,

44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

McDonnell Douglas: Docket 97–NM–242–

AD.

Applicability: Model DC–8 series

airplanes equipped with a lavatory

drainage system; certificated in any

category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

modified, altered, or repaired in the area

subject to the requirements of this AD. For

airplanes that have been modified, altered, or

repaired so that the performance of the

requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (d) of this AD.

The request should include an assessment of

the effect of the modification, alteration, or

repair on the unsafe condition addressed by

this AD; and, if the unsafe condition as not

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

previously accomplished.

To prevent engine damage, airframe

damage, and/or hazard to persons or property

on the ground as a result of ‘‘blue ice’’ that

has formed from leakage of the lavatory drain

system or flush/fill system and dislodged

from the airplane, accomplish the following:

(a) Accomplish the applicable

requirements of paragraphs (a)(1) through

(a)(9) of this AD at the time specified in each

paragraph. For the waste drain system of any

lavatory that incorporates more than one type

of valve, only one of the waste drain system

leak test procedures (the one that applies to

the equipment with the longest leak test

interval) must be conducted at each service

panel location. During the performance of the

waste drain system valve leak tests specified

in this AD, fluid shall completely cover the

upstream end of the valve being tested. The

direction of the 3 pounds per square inch

differential pressure (PSID) shall be applied

in the same direction as occurs in flight; the

other waste drain system valves shall be

open, and the minimum time to maintain the

differential pressure shall be 5 minutes. Any

revision of the seal change intervals or leak

test intervals must be approved by the

Manager, Los Angeles Aircraft Certification

Office (ACO), FAA, Transport Airplane

Directorate.

Note 2: Inclusion of a valve in this AD does

not mean that the valve has been certified for

installation in DC–8 series airplanes.

Certification of the valve for installation in

the airplane must be accomplished by means

acceptable to the FAA, if the valve has not

been previously certified.

(1) Replace the valve seals with new valve

seals in accordance with the applicable

schedule specified in paragraphs (a)(1)(i),

(a)(1)(ii), and (a)(1)(iii) of this AD.

(i) For each lavatory drain system that has

an in-line drain valve installed, Kaiser

Electroprecision part number (p/n) series

2651–278: Replace the seals within 5,000

flight hours after the effective date of this AD,

or within 48 months after the last

documented seal change, whichever occurs

later. Thereafter, replace the seals at intervals

not to exceed 48 months.

(ii) For each lavatory drain system that has

a Pneudraulics part number series 9527

valve: Replace the seals within 5,000 flight

hours after the effective date of this AD, or

within 18 months after the last documented

seal change, whichever occurs later.

Thereafter, replace the seals at intervals not

to exceed 18 months or 6,000 flight hours,

whichever occurs later.

(iii) For each lavatory drain system that has

any other type of drain valve: Replace the

seals within 5,000 flight hours after the

effective date of this AD, or within 18 months

after the last documented seal change,

whichever occurs later. Thereafter, replace

the seals at intervals not to exceed 18

months.

(2) For each lavatory drain system that has

an in-line drain valve installed, Kaiser

Electroprecision p/n series 2651–278: Within

4,500 flight hours after the effective date of

this AD, and thereafter at intervals not to

exceed 4,500 flight hours, accomplish the

procedures specified in paragraphs (a)(2)(i)

and (a)(2)(ii) of this AD.

(i) Conduct a leak test of the toilet tank

dump valve (in-tank valve that is spring

loaded closed and operable by a T-handle at

the service panel) and the in-line drain valve.

The toilet tank dump valve leak test must be

performed by filling the toilet tank with a

minimum of 10 gallons of water/rinsing fluid

and testing for leakage after a period of 5

minutes. Take precautions to avoid

overfilling the tank and spilling fluid into the

airplane. The in-line drain valve leak test

must be performed with a minimum of 3

PSID applied across the valve.

(ii) If a service panel valve or cap is

installed, perform a visual inspection to

detect wear or damage that may allow

leakage of the service panel drain valve outer

cap/door seal and the inner seal (if the valve

has an inner door with a second positive

seal), and the seal mating surfaces.

(3) For each lavatory drain system that has

a service panel drain valve installed,

Pneudraulics p/n series 9527: Within 2,000

flight hours after the effective date of this AD,

and thereafter at intervals not to exceed 2,000

flight hours, accomplish the procedures

specified in paragraphs (a)(3)(i) and (a)(3)(ii)

of this AD.

(i) Conduct a leak test of the toilet tank

dump valve and the service panel drain
Federal Register / Vol. 63, No. 131 /Thursday, July 9, 1998 / Proposed Rules 37077

valve. The toilet tank dump valve leak test

must be performed by filling the toilet tank

with a minimum of 10 gallons of water/

rinsing fluid and testing for leakage after a

period of 5 minutes. Take precautions to

avoid overfilling the tank and spilling fluid

into the airplane. The leak test of the service

panel drain valve must be performed with a

minimum of 3 PSID applied across the valve

inner door/closure device.

(ii) Perform a visual inspection of the outer

cap/door and seal mating surface for wear or

damage that may cause leakage.

(4) For each lavatory drain system that has

a service panel drain valve installed, Kaiser

Electroprecision p/n series 0218–0032, or

Shaw Aero Devices part number/serial

number as listed in Table 1 of this AD:

Within 1,000 flight hours after the effective

date of this AD, and thereafter at intervals not

to exceed 1,000 flight hours, accomplish the

procedures specified in paragraphs (a)(4)(i)

and (a)(4)(ii) of this AD.

TABLE 1.—SHAW AERO VALVES APPROVED FOR 1,000 FLIGHT HOUR LEAK TEST INTERVAL

Shaw waste drain valve part No. Serial No. of part No. Valve approved for 1,000-hour leak test interval

331 Series, 332 Series ............................................................................. All.

10101000B–A ........................................................................................... None.

10101000B–A–1 ....................................................................................... 0207–0212, 0219, 0226 and higher.

10101000BA2 ........................................................................................... 0130 and higher.

10101000C–A–1 ....................................................................................... 0277 and higher.

10101000C–J ............................................................................................ None.

10101000C–J–2 ........................................................................................ None.

10101000CN OR C–N .............................................................................. 3649 and higher.

Certain 10101000B valves ....................................................................... Any of these ‘‘B’’ series valves that incorporate the improvements of

Shaw Service Bulletin 10101000B–38–1, dated October 7, 1994, and

are marked ‘‘SBB38–1–58’’.

Certain 10101000C valves ....................................................................... Any of these ‘‘C’’ series valves that incorporate the improvements of

Shaw Service Bulletin 10101000C–38–2 dated October 7, 1994, and

are marked ‘‘SBC38–2–58’’.

(i) Conduct a leak test of the toilet tank

dump valve and service panel drain valve.

The toilet tank dump valve leak test must be

performed by filling the toilet tank with a

minimum of 10 gallons of water/rinsing fluid

and testing for leakage after a period of 5

minutes. Take precautions to avoid

overfilling the tank and spilling fluid into the

airplane. The service panel drain valve leak

test must be performed with a minimum of

3 PSID applied across the valve inner door/

closure device.

(ii) Perform a visual inspection of the outer

cap/door and seal mating surface for wear or

damage that may cause leakage.

(5) For each lavatory drain system that has

a service panel drain valve installed, Kaiser

Electroprecision p/n series 0218–0026; or

Shaw Aero Devices p/n series 10101000B or

10101000C [except as specified in paragraph

(a)(4) of this AD]: Within 600 flight hours

after the effective date of this AD, and

thereafter at intervals not to exceed 600 flight

hours, accomplish the procedures specified

in paragraphs (a)(5)(i) and (a)(5)(ii) of this

AD.

(i) Conduct a leak test of the toilet tank

dump valve and the service panel drain

valve. The leak test of the toilet tank dump

valve must be performed by filling the toilet

tank with a minimum of 10 gallons of water/

rinsing fluid and testing for leakage after a

period of 5 minutes. Take precautions to

avoid overfilling the tank and spilling fluid

into the airplane. The service panel drain

valve leak test must be performed with a

minimum of 3 PSID applied across the valve

inner door/closure device.

(ii) Perform a visual inspection of the outer

cap/door and seal mating surface for wear or

damage that may cause leakage.

(6) For each lavatory drain system with a

lavatory drain system valve that incorporates

either ‘‘donut’’ plug, Kaiser Electroprecision

p/n’s 4259–20 or 4259–31; Kaiser Roylyn/

Kaiser Electroprecision cap/flange p/n’s

2651–194C, 2651–197C, 2651–216, 2651–

219, 2651–235, 2651–256, 2651–258, 2651–

259, 2651–260, 2651–275, 2651–282, 2651–

286; Shaw Aero Devices assembly p/n 0008–

100; or other FAA-approved equivalent parts;

accomplish the requirements of paragraphs

(a)(6)(i), (a)(6)(ii), and (a)(6)(iii) of this AD at

the times specified in those paragraphs. For

the purposes of this paragraph [(a)(6)], ‘‘FAAapproved equivalent part’’ means either a

‘‘donut’’ plug which mates with the cap/

flange p/n’s listed above, or a cap/flange

which mates with the ‘‘donut’’ plug p/n’s

listed above, such that the cap/flange and

‘‘donut’’ plug are used together as an

assembled valve.

(i) Within 200 flight hours after the

effective date of this AD, and thereafter at

intervals not to exceed 200 flight hours,

conduct leak tests of the toilet tank dump

valve and the service panel drain valve. The

leak test of the toilet tank dump valve must

be performed by filling the toilet tank with

a minimum of 10 gallons of water/rinsing

fluid and testing for leakage after a period of

5 minutes. Take precautions to avoid

overfilling the tank and spilling fluid into the

airplane. The service panel drain valve leak

test must be performed with a minimum 3

PSID applied across the valve.

(ii) Perform a visual inspection of the outer

door/cap and seal mating surface for wear or

damage that may cause leakage. This

inspection shall be accomplished in

conjunction with the leak tests of paragraph

(a)(6)(i).

(iii) Within 5,000 flight hours after the

effective date of this AD, replace all the

‘‘donut’’ valves identified in paragraph (a)(6)

of this AD with another type of FAAapproved valve. Following installation of the

replacement valve, perform the appropriate

leak tests and seal replacements at the

intervals specified for that replacement valve,

as applicable.

(7) For each lavatory drain system not

addressed in paragraphs (a)(2), (a)(3), (a)(4),

(a)(5), and (a)(6) of this AD: Within 200 flight

hours after the effective date of this AD, and

thereafter at intervals not to exceed 200 flight

hours, accomplish the procedures specified

in paragraphs (a)(7)(i) and (a)(7)(ii) of this

AD.

(i) Conduct a leak test of the toilet tank

dump valve and the service panel drain

valve. The toilet tank dump valve leak test

must be performed by filling the toilet tank

with a minimum of 10 gallons of water/

rinsing fluid and testing for leakage after a

period of 5 minutes. Take precautions to

avoid overfilling the tank and spilling fluid

into the airplane. The leak test of the service

panel drain valve must be performed with a

minimum of 3 PSID applied across the valve

inner door/closure device.

(ii) Perform a visual inspection of the outer

cap/door and seal mating surface for wear or

damage that may cause leakage.

(8) For flush/fill lines: Within 5,000 flight

hours after the effective date of this AD,

perform the requirements of paragraph

(a)(8)(i) or (a)(8)(ii), as applicable; and

paragraph (a)(8)(iii) of this AD. Thereafter,

repeat these requirements at intervals not to

exceed 5,000 flight hours, or 48 months after

the last documented seal change, whichever

occurs later.

(i) If a lever lock cap is installed on the

flush/fill line of the subject lavatory, replace

the seals on the toilet tank anti-siphon

(check) valve and the flush/fill line cap.

Perform a leak test of the toilet tank antisiphon (check) valve with a minimum of 3

PSID across the valve, in accordance with the

applicable portions of paragraph (a)(8)(ii)(A)

of this AD.

(ii) If a vacuum breaker check valve,

Monogram p/n series 3765–190, or Shaw

Aero Devices p/n series 301–0009–01 is

installed on the subject lavatory, replace the

seals/o-rings in the valve. Perform a leak test

of the vacuum breaker check valve and verify

proper operation of the vent line vacuum

breaker, in accordance with paragraphs

(a)(8)(ii)(A) and (a)(8)(ii)(B) of this AD.
37078 Federal Register / Vol. 63, No. 131 /Thursday, July 9, 1998 / Proposed Rules

(A) Leak test the toilet tank anti-siphon

(check) valve or the vacuum breaker check

valve by filling the toilet tank with water/

rinsing fluid to a level such that the bowl is

approximately half full (at least 2 inches

above the flapper in the bowl). Apply 3 PSID

across the valve in the same direction as

occurs in flight. The vent line vacuum

breaker on vacuum breaker check valves

must be pinched closed or plugged for this

leak test. If there is a cap/valve at the flush/

fill line port, the cap/valve must be removed/

open during the test. Check for leakage at the

flush/fill line port for a period of 5 minutes.

(B) Verify proper operation of the vent line

vacuum breaker by filling the tank and

checking at the fill line port for back drainage

after disconnecting the fluid source from the

flush/fill line port. If back drainage does not

occur, replace the vent line vacuum breaker

or repair the vacuum breaker check valve, in

accordance with the component maintenance

manual to obtain proper back drainage. As an

alternative to the test technique specified

above, verify proper operation of the vent

line vacuum breaker in accordance with the

procedures of the applicable component

maintenance manual.

(iii) If a flush/fill ball valve, Kaiser

Electroprecision p/n series 0062–0009, is

installed on the flush/fill line of the subject

lavatory, replace the seals in the flush/fill

ball valve and the toilet tank anti-siphon

valve. Perform a leak test of the toilet tank

anti-siphon valve with a minimum of 3 PSID

across the valve, in accordance with

paragraph (a)(8)(ii)(A) of this AD.

(9) If leakage is discovered during any leak

test or inspection required by paragraph (a)

of this AD, or if evidence of leakage is found

at any other time, accomplish the

requirements of paragraph (a)(9)(i), (a)(9)(ii),

or (a)(9)(iii) of this AD, as applicable.

(i) If a leak is discovered, prior to further

flight, repair the leak. Prior to further flight

after repair, perform the appropriate leak test

as specified in paragraph (a) of this AD, as

applicable. Additionally, prior to returning

the airplane to service, clean the surfaces

adjacent to where the leakage occurred to

clear them of any horizontal fluid residue

streaks; such cleaning must be to the extent

that any future appearance of a horizontal

fluid residue streak will be taken to mean

that the system is leaking again.

Note 3: For purposes of this AD, ‘‘leakage’’

is defined as any visible leakage, if observed

during a leak test. At any other time (than

during a leak test), ‘‘leakage’’ is defined as

the presence of ice in the service panel, or

horizontal fluid residue streaks/ice trails

originating at the service panel. The fluid

residue is usually, but not necessarily, blue

in color.

(ii) If any worn or damaged seal is found,

or if any damaged seal mating surface is

found, prior to further flight, repair or replace

it in accordance with the valve

manufacturer’s maintenance manual.

(iii) In lieu of performing the requirements

of paragraph (a)(9)(i) or (a)(9)(ii): Prior to

further flight, drain the affected lavatory

system and placard the lavatory inoperative

until repairs can be accomplished.

(b) For all airplanes: Unless accomplished

previously, within 5,000 flight hours after the

effective date of this AD, perform the actions

specified in either paragraph (b)(1) or (b)(2)

of this AD:

(1) Install an FAA-approved lever lock cap

on the flush/fill lines for all lavatories. Or

(2) Install a vacuum break, Monogram p/n

series 3765–190, or Shaw Aero Devices p/n

series 301–0009–01, in the flush/fill lines for

all lavatories. Or

(3) Install a flush/fill ball valve, Kaiser

Electroprecision p/n series 0062–0009 on the

flush/fill lines for all lavatories.

(c) For any affected airplane acquired after

the effective date of this AD: Before any

operator places into service any airplane

subject to the requirements of this AD, a

schedule for the accomplishment of the leak

tests required by this AD shall be established

in accordance with either paragraph (c)(1) or

(c)(2) of this AD, as applicable. After each

leak test has been performed once, each

subsequent leak test must be performed in

accordance with the new operator’s schedule,

in accordance with paragraph (a) of this AD.

(1) For airplanes that have been maintained

previously in accordance with this AD, the

first leak test to be performed by the new

operator must be accomplished in

accordance with the previous operator’s

schedule or with the new operator’s

schedule, whichever results in the earlier

accomplishment date for that leak test.

(2) For airplanes that have not been

previously maintained in accordance with

this AD, the first leak test to be performed by

the new operator must be accomplished prior

to further flight, or in accordance with a

schedule approved by the FAA Principal

Maintenance Inspector (PMI), but within a

period not to exceed 200 flight hours.

(d) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Los

Angeles ACO. Operators shall submit their

requests through an appropriate FAA PMI,

who may add comments and then send it to

the Manager, Los Angeles ACO.

Note 4: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(e) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

Issued in Renton, Washington, on July 1,

1998.

S.R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–18158 Filed 7–8–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–01–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A320 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

Airbus Model A320–111, –211, –212,

and –231 series airplanes, that currently

requires reinforcement of the tail section

of the fuselage at frames 68 and 69. That

AD was prompted by reports indicating

that the tail section has struck the

runway during takeoffs and landings.

This action would add a requirement for

reinforcement of the tail section of the

fuselage at frames 65 to 67. This action

also would revise the applicability of

the existing AD. The actions specified

by the proposed AD are intended to

prevent structural damage to the tail

section when it strikes the runway,

which could result in depressurization

of the fuselage during flight.

DATES: Comments must be received by

August 10, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 98–NM–

01–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays.

The service information referenced in

the proposed rule may be obtained from

Airbus Industrie, 1 Rond Point Maurice

Bellonte, 31707 Blagnac Cedex, France.

This information may be examined at

the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW.,

Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Norman B. Martenson, Manager,

International Branch, ANM–116, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2110;

fax (425) 227–1149.